The United States Friday welcomed the acquittal by Zimbabwe's high court of opposition leader Morgan Tsvangirai on treason charges. The State Department said it hopes the action leads to new political dialogue in the troubled country.

The Bush administration, which has long been critical of moves against the political opposition in Zimbabwe including the trial of Mr. Tsvangirai, is welcoming the acquittal, and expressing hope it leads to political dialogue and electoral reform in that country.

At a news briefing, State Department Spokesman Richard Boucher said he hopes the verdict signals the end of politically motivated prosecutions in Zimbabwe, and opens the door to "constructive dialogue" between Zimbabwe's political parties.

He also said the United States is hopeful the trial outcome is a signal that the government of President of Robert Mugabe is ready to approach parliamentary elections next March with fairness guidelines like those recently approved by the Southern Africa Development Community, SADC.

However, Mr. Boucher said reforms now under consideration by the Mugabe government fail to address "fundamental flaws" that produced bitter disputes after elections there two years ago.

"For these parliamentary elections to be free and fair, we think that a number of steps are necessary, including establishing a truly independent election commission, insuring balanced media access for all the political parties, assuring freedom of assembly and political campaigning, and suppressing political violence," said Mr. Boucher. "Those are the kind of steps that we are looking for. If this positive development of the acquittal is to lead to anything better, it's going to have to be followed by serious steps like these for electoral reform."

The SADC election guidelines were approved by member states of the regional grouping including Zimbabwe at a meeting in Mauritius in August, and call for, among other things, impartial electoral institutions and clear provisions for dealing with election disputes.

Mr. Tsvangirai was first accused of treason two weeks before his defeat by Mr. Mugabe in a presidential election in March, 2002 widely criticized as having been marred by fraud.

The United States said the election was neither free nor fair, and later joined European Union countries in imposing travel and financial sanctions against Mr. Mugabe and close associates.